Explosive composition and method of making



Patented Jan. 30, 1934 UNITE EXPLOSIVE COMPOSITION AND METHOD or MAKINGClifford A. Woodbury, Media, Pa., assignor to E. I. du Pont cle Nemours& Company, Wilmington, Del., a corporation of Delaware No Drawing.

Application May 23, 1931 Serial No. 539,630

14 Claims.

My invention relates to a high explosive composition and moreparticularly to a high explosive composition from which other explosivecompositions of different types and strengths can subsequently be made.

High explosives of different types, as made at the present time,comprise mixtures of a variety of different ingredients. Among theingredients used are nitroglycerin and similar nitric esters,gelatinizing agents for the nitroglycerin, various oxygen carryingingredients, such as ammonium nitrate, sodium nitrate, potassiumchlorate, etc., absorbents for the nitroglycerin, such as wood pulp,starch, flour, corn meal and other different materials of similarcomposition, anti-acid materials, such as chalk for neutralizingincipient acidity that may develop, sulphur, sodium chloride and variousother materials.

The materials mentioned above are all used for specific reasons andaccording to well defined principles which are familiar to those skilledin the art. By varying the proportions and kinds of the variousingredients used, it is readily possible to control the strength,density, velocity, sensitiveness, water resistance, fumes and otherproperties of the explosive to suit the purpose to which the explosiveis to be applied According to the ingredients used in dynamites andtheir properties, various well recognized types of dynamites areproduced which are classified by those skilled in the art, into thefollowing general groups:

. Straight dynamites Ammonia dynamites Gelatin dynamites Ammoniagelatins Permissible dynamites It will be seen from the above that thereare many types of high explosive compositions and that their propertiesare the result of formulating the powders according to certain definiteand well defined principles.

Dynamite manufacture, at the present time, is carried out in plants ofconsiderable size, and must, of necessity, involve many preliminaryoperations. Among such operations may be mentioned the preparation andmixing of nitrating acids, the manufacture of ammonium nitrate, thepreparation and control of various non-explosive ingredients, includingtheir drying, grinding, and screening, as well as the manufacture ofnitroglycerin and the disposal of the nitrating waste acids. The aboveoperations are costly and complicated, and require central manufacturingouawgor types of dynamites desired. No other method 5 of producing thevarious explosives required has been possible prior to the presentinvention.

The manufacture of the finished dynamite at central explosive plants hasbeen necessary because of the fact that it is impossible to transport 55safely large quantities of nitroglycerin. Nitroglycerin is a necessaryingredient in all the usual dynamite compositions, and is the mosthazardous to produce of the various ingredients.

The shipment of nitroglycerin by itself on railroads, for example, isout of the question from a safety point of view.

The transportation of nitroglycerin after its simple absorption in thenecessary amount of materials such as wood pulp, is comparatively safeprovided the mixture does not contain more than 60 percent ofnitroglycerin. 75 percent straight dynamite is manufactured but, forreasons of safety, must be transported by water.

This is necessary because of the possibility of so exudation ofnitroglycerin from the absorbent causing a dangerous condition.

It will be readily apparent to one skilled in the art that only a verylimited number of different explosives having very limited propertiescould be manufactured from these high strength straight dynamites.Various high nitroglycerin content gelatins are commonly sold in whichthe nitroglycerin is fixed by gelatinization with varying amounts ofnitrocotton but the proportions usually employed give a gelatin so firmthat it cannot subsequently be broken up and mixed with other materialsto form a satisfactory dynamite.

I have now discovered a new and improved method for renderingnitroglycerin safe for transportation, at the same time maintaining itin such mixtures as to allow of its subsequent use in explosives. I havefound that the use of mixtures of the following compositions gives thedesired advantages, and that the heretofore inherout disadvantages arethereby overcome.

In mixtures of the above compositions, a balance is maintained, withincreasing nitroglycerin content, between the two mixing materials,nitrono cotton and wood pulp. This is done by increasing the amount ofnitrocotton as the nitroglycerin content is increased and the wood pulpcontent decreased. By proceeding thus, a decrease in the amount ofabsorbent is compensated for by an increase in viscosity andgelatinization. The increased gelatinization automatically reduces theamount of wood pulp necessary to hold the nitroglycerin securely. Theamount of nitrocotton must be so controlled as to produce a product ofsatisfactory physical characteristics.

The compositions described above are permissible for shipment: They donot allow the exudation of nitroglycerin, and are sufiiciently low inviscosity so that they can subsequently be coinbined with otheringredients to form the different compositions desired.

There are many possible combinations of materials, which are within thescope of my invention. However, I prefer to use as a startingcomposition, one consisting of per cent nitroglycerin, 1 per cent nitroott n, 13 per cent wood pulp and l per cent chalk. With the abovestarting composition, it is possible to manufacture any of theabove-mentioned five general classes of explosives. For example, if Iwish to manufacture to per cent straight nitroglycerin dynamite, I mayuse i7 pounds of the above-mentioned starting composition and 53 poundsof non-explosive ingredients consisting of 9 pounds of wood pulp and 2Mpounds of sodium nitrate. If I wish to make to per cent straightnitroglycerin gelatin dynamite, I may use 58.9 pounds of theabovementioned. starting mixture, 43.1 pounds of sodi um and 1 pound ofcorn meal.

The composition may also be any one of those covered by my copendingapplication, Serial No. 539,631, filed May 23, 1931.

From the composition described practically all the standard dynamitescan be made when the proper amounts of other readily available materialsare mixed with the starting composition. The different compositions canbe incorporated in standard mixing equipment and the powders are foundto have the properties desired.

The advantages of my new method of compounding high explosivecompositions can be readily seen. The new method permits high explosivesof all types to be made without the necessity of manufacturingnitroglycerin at the same place. By using this method, it is possiblefor mixtures containing high percentages of nitroglycerin to betransported safely, and to be mixed elsewhere subsequently with thedesired proportions of ingredients available locally. Substantialsavings in transportation costs can be thus realized. Other advantageswill readily suggest themselves to those skilled in the art.

It is to be understood that various minor changes may be made in thecompositions without departing from the spirit of the invention. Forexample, in place of nitroglycerin alone, this compound may be usedmixed with various similar materials such as are frequently used for thedepression of its freezing point. Such materials comprise nitratedpolymerized glycerin, nitrated sugars, nitroglycol, nitratedchlorhydrins, etc. Similarly, in place of wood pulp, other carbonaceouscombustible materials of relatively high absorption value may be used,such as, for example, balsa wood, bagasse pith, and other various pithymaterials.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit thereof, it is to be understoodthat I do not limit myself to the foregoing examples or descriptionsexcept as indicated in the following patent claims.

I claim:

1. An explosive composition capable of being subsequently combined withadditional ingredients to form various types 'of nitroglycerin highexplosives which composition comprises between 75 and percent of atleast one liquid nitric ester, between 0.5 and 2.5 per cent of agelatinizing agent, and between 23.5 and 6.5 per cent of a combustibleabsorbent material.

2. An explosive composition capable of being subsequently combined withadditional ingredients to form various types of nitroglycerin highexplosives which composition comprises between 75 and 90 per centnitroglycerin, between 0.5 and 2.5 per cent of a gelatinizing agent forthe nitroglycerin, and between 23.5 and 6.5 per cent of an absorbentmaterial.

3. An explosive composition capable of being subsequently combined withadditional ingredients to form various types of nitroglycerin highexplosives which composition comprises between 7 5 and 90 per centnitroglycerin, between 0.5 and 2.5 of a gelatinizing agent, and between23.5 and 6.5 per cent of a combustible absorbent material.

a. An explosive composition capable of being subsequently combined withadditional ingredients to form various types of nitroglycerin highexplosives which composition comprises between '75 and 90 per centnitroglycerin, between 0.5 and 2.5 per cent nitrocotton, and between23.5 and 6.5 per cent of a combustible absorbent material.

5. An explosive composition capable of being subsequently mixed withadditional ingredients to form various types of nitroglycerin highexplosives, which composition comprises between 75 and 90 per centnitroglycerin, between 0.5 and 2.5 per cent nitrocotton, and between23.5 and 6.5 per cent wood pulp.

6. An explosive composition capable of being subsequently combined withadditional ingredients to form various types of nitroglycerin highexplosives which composition comprises about 85 per cent nitroglycerin,about 1 per cent nitrocotton, and about 13 per cent combustibleabsorbent material.

7. An explosive composition capable of being subsequently combined withadditional ingredients to form various types of nitroglycerin highexplosives, which composition comprises about 85 per cent nitroglycerin,about 1 per cent nitrocotton, about 13 per cent wood pulp, and about 1per cent chalk.

8. A method of manufacturing a dynamite composition which comprisespreparing a substantially unbalanced explosive composition comprisingnitroglycerin and less than the normal amount of non-explosive or dopeingredients required to produce a finished dynamite composition,compensating for the decrease in the amount of absorbent by introducinga small amount of nitrocotton so as to' increase the viscosity andgelatinization of the product to hold the nitroglycerin in place againstleakage, thereby producing a composition having physical characteristicsrendering it safe for handling and transportation, and subsequentlycombining therewith the dope ingredients to produce a dynamite of lowernitroglycerin content.

9. A method of manufacturing a dynamite composition which comprisespreparing a substantially unbalanced explosive composition substantiallyfree of oxygen yielding salts comprising nitroglycerin and less than thenormal amount of non-explosive or dope ingredients required to produce afinished dynamite composition, compensating for the decrease in theamount of absorbent by introducing a small amount of nitrocotton so asto increase the viscosity and gelatinization of the product to hold thenitroglycerin in place against leakage, thereby producing a compositionhaving physical characteristics rendering it safe for handling andtransportation, and subsequently combining therewith the dopeingredients to produce a dynamite of lower nitroglycerin content.

10. A method of manufacturing a dynamite composition which comprisespreparing a substantially unbalanced explosive composition comprisingnitroglycerin and less than the normal amount of non-explosive or "dopeingredients required to produce a finished dynamite composition,compensating for the decrease in the amount of absorbent by introducingnot more than 2.5 per cent. nitrocotton, thereby producing a compositionhaving physical charactertistics rendering it safe for handling andtransportation, and subsequently combining therewith the dopeingredients to produce a dynamite of lower nitroglycerin content.

11. A method of manufacturing a dynamite composition which comprisespreparing a substantially unbalanced explosive composition containingsubstantiallybetween and 90 per cent. of at least one liquid nitricester, between 0.5

and 2.5 per cent. of a gelatinizing agent for the nitric ester, andbetween 23.5 and 6.5 per cent. of an absorbent material, thereby makinga composition having physical characteristics that render it safe forhandling and transportation, and subsequently breaking down thecomposition and combining therewith the dope" ingredients to produce adynamite of lower nitroglycerin content.

12. The method of claim 11 in which the combustible absorbent materialis a combustible taken from a group consisting of wood pulp, starch,flour, vegetable piths, and a cereal prodnot.

13. A method of manufacturing a dynamite composition which comprisespreparing a substantially unbalanuced explosive composition containingsubstantially between '75 and 90 per cent. nitroglycerin, between 0.5and 2.5 per cent. of a gelatinizing agent for the nitroglycerin, andbetween 23.5 and 6.5 per cent. of an absorbent material, thereby makinga composition having physical characteristics that render it safe forhandling and transportation, and subsequently breaking down thecomposition and combining therewith the dope ingredients to produce adynamite of lower nitroglycerin content.

14. The method of claim 13 in which the combustible absorbent materialis a combustible taken from a group consisting of wood pulp, starch,flour, vegetable piths, and a cerial product.

CLIFFORD A. WOODIBURY.

